<?php
/**
 * CPhpMessageSource class file.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @link http://www.yiiframework.com/
 * @copyright Copyright &copy; 2008-2011 Yii Software LLC
 * @license http://www.yiiframework.com/license/
 */

/**
 * CPhpMessageSource represents a message source that stores translated messages in PHP scripts.
 *
 * CPhpMessageSource uses PHP files and arrays to keep message translations.
 * <ul>
 * <li>All translations are saved under the {@link basePath} directory.</li>
 * <li>Translations in one language are kept as PHP files under an individual subdirectory
 *   whose name is the same as the language ID. Each PHP file contains messages
 *   belonging to the same category, and the file name is the same as the category name.</li>
 * <li>Within a PHP file, an array of (source, translation) pairs is returned.
 * For example:
 * <pre>
 * return array(
 *     'original message 1' => 'translated message 1',
 *     'original message 2' => 'translated message 2',
 * );
 * </pre>
 * </li>
 * </ul>
 * When {@link cachingDuration} is set as a positive number, message translations will be cached.
 *
 * Starting from version 1.0.10, messages for an extension class (e.g. a widget, a module) can be specially managed and used.
 * In particular, if a message belongs to an extension whose class name is Xyz, then the message category
 * can be specified in the format of 'Xyz.categoryName'. And the corresponding message file
 * is assumed to be 'BasePath/messages/LanguageID/categoryName.php', where 'BasePath' refers to
 * the directory that contains the extension class file. When using Yii::t() to translate an extension message,
 * the category name should be set as 'Xyz.categoryName'.
 *
 * @author Qiang Xue <qiang.xue@gmail.com>
 * @version $Id: CPhpMessageSource.php 2798 2011-01-01 19:29:03Z qiang.xue $
 * @package system.i18n
 * @since 1.0
 */
class CPhpMessageSource extends CMessageSource
{
    const CACHE_KEY_PREFIX='Yii.CPhpMessageSource.';

    /**
     * @var integer the time in seconds that the messages can remain valid in cache.
     * Defaults to 0, meaning the caching is disabled.
     */
    public $cachingDuration=0;
    /**
     * @var string the ID of the cache application component that is used to cache the messages.
     * Defaults to 'cache' which refers to the primary cache application component.
     * Set this property to false if you want to disable caching the messages.
     * @since 1.0.10
     */
    public $cacheID='cache';
    /**
     * @var string the base path for all translated messages. Defaults to null, meaning
     * the "messages" subdirectory of the application directory (e.g. "protected/messages").
     */
    public $basePath;

    private $_files=array();

    /**
     * Initializes the application component.
     * This method overrides the parent implementation by preprocessing
     * the user request data.
     */
    public function init()
    {
        parent::init();
        if($this->basePath===null)
        $this->basePath=Yii::getPathOfAlias('application.messages');
    }

    /**
     * Determines the message file name based on the given category and language.
     * If the category name contains a dot, it will be split into the module class name and the category name.
     * In this case, the message file will be assumed to be located within the 'messages' subdirectory of
     * the directory containing the module class file.
     * Otherwise, the message file is assumed to be under the {@link basePath}.
     * @param string $category category name
     * @param string $language language ID
     * @return string the message file path
     * @since 1.0.10
     */
    protected function getMessageFile($category,$language)
    {
        if(!isset($this->_files[$category][$language]))
        {
            if(($pos=strpos($category,'.'))!==false)
            {
                $moduleClass=substr($category,0,$pos);
                $moduleCategory=substr($category,$pos+1);
                $class=new ReflectionClass($moduleClass);
                $this->_files[$category][$language]=dirname($class->getFileName()).DIRECTORY_SEPARATOR.'messages'.DIRECTORY_SEPARATOR.$language.DIRECTORY_SEPARATOR.$moduleCategory.'.php';
            }
            else
            $this->_files[$category][$language]=$this->basePath.DIRECTORY_SEPARATOR.$language.DIRECTORY_SEPARATOR.$category.'.php';
        }
        return $this->_files[$category][$language];
    }

    /**
     * Loads the message translation for the specified language and category.
     * @param string $category the message category
     * @param string $language the target language
     * @return array the loaded messages
     */
    protected function loadMessages($category,$language)
    {
        $messageFile=$this->getMessageFile($category,$language);

        if($this->cachingDuration>0 && $this->cacheID!==false && ($cache=Yii::app()->getComponent($this->cacheID))!==null)
        {
            $key=self::CACHE_KEY_PREFIX . $messageFile;
            if(($data=$cache->get($key))!==false)
            return unserialize($data);
        }

        if(is_file($messageFile))
        {
            $messages=include($messageFile);
            if(!is_array($messages))
            $messages=array();
            if(isset($cache))
            {
                $dependency=new CFileCacheDependency($messageFile);
                $cache->set($key,serialize($messages),$this->cachingDuration,$dependency);
            }
            return $messages;
        }
        else
        return array();
    }
}